/*
* Copyright 2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.data.hadoop.store.expression;
import java.util.Arrays;
import java.util.List;
import org.springframework.expression.AccessException;
import org.springframework.expression.EvaluationContext;
import org.springframework.expression.MethodExecutor;
import org.springframework.expression.TypedValue;
/**
* A {@link MethodExecutor} using an first argument as key
* to be used as a range search with a List of Object found from
* a second argument.
*
* <p> Spel expression for this would be "range(region,{10,20,30,40})".
* Value 15 would create key "20_range", 40 key "40_range" and
* 45 key "40_range".
*
* @author Janne Valkealahti
*
*/
public class HashRangeMethodExecutor implements MethodExecutor {
@Override
public TypedValue execute(EvaluationContext context, Object target, Object... arguments) throws AccessException {
if (arguments[1] instanceof List) {
try {
Object[] ranges = ((List<?>) arguments[1]).toArray(new Object[0]);
int searchIndex = Arrays.binarySearch(ranges, arguments[0]);
return new TypedValue(ranges[Math.min(searchIndex < 0 ? -searchIndex - 1 : searchIndex, ranges.length - 1)]
+ "_range");
} catch (Exception e) {
throw new AccessException("Error finding range", e);
}
}
throw new AccessException("Argument " + arguments[1] + " not a List");
}
}